Fauna
Fish

Blue Shark

Prionace glauca

Also known as Great Blue Shark

Blue sharks cut through pelagic waters with an exceptionally slender, hydrofoil-like silhouette, cruising ocean gyres on massive migrations spanning thousands of kilometers. Females give birth to litters of up to one hundred live pups after a year-long gestation, relying on deeply serrated teeth to grip slippery squid and schooling fish during deep night dives. Intense longline fishing pressure across open-ocean shipping corridors continues to diminish their numbers worldwide.

PelagicMigratoryCarnivorous
Blue Shark reference1 / 7
(c) Marion Kraschl, some rights reserved (CC BY) · cc-by
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Near ThreatenedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNear ThreatenedRed List categories, explained →
Key facts
Diet & preyPelagic Squid, Atlantic Mackerel, Pacific Herring
Predators
  • Killer Whale
  • Great White Shark
  • Shortfin Mako
ThreatsCommercial longline bycatch, shark finning, marine debris
HabitatsOpen ocean, pelagic zones from surface to 350 meters depth
Life span15–20 years
Classification
  1. FamilyCarcharhinidae
  2. SpeciesPrionace glauca
Range & activity
Range data is not available yet.
Safe observation
Interaction riskHigh
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is high
Large pelagic predator capable of severe bites; maintain eye contact and keep distance while diving.
Why it is dangerous
Possesses razor-sharp, serrated teeth and curious exploratory behavior that can result in exploratory bites and severe lacerations.
How to recognize a risky encounter
Look for a brilliant indigo-blue dorsal surface, white underside, long pointed snout, and slender, swept-back pectoral fins.
What to do
Keep full visual contact, place a solid barrier like a camera rig between you and approaching individuals, and retreat calmly.
What to notice
Recognizable in deep offshore waters by its slender profile and vivid cobalt coloration, lacking dark fin margins.
Support conservation
If accidentally hooked on fishing gear, cut the line as close to the hook as safely possible to maximize post-release survival.
Responsible observation
  • Diving Etiquette: Maintain calm body posture and continuous 360-degree awareness without erratic thrashing.
  • Baiting Precautions: Avoid remaining in the water during chumming activities, as scent stimulates investigative bumps.
Related species
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